You can't "reveal" something that's not hidden in the first place, though.
Even if you expand the definition of "reveal" to mean "point out to outside sources," that's still not what Joe/Ars did. Other sources discovered this information all on their own.
As I keep saying, you may think that this sort of article is "below" Ars' normal standards, and that's a perfectly valid opinion, but I just don't see how there's just any reasonable way to conclude that Ars leaked, revealed, or "betrayed" anything.
I *do* agree with you that the wording was ... unfortunate, to put it mildly, in that it definitely seems to tacitly, if not explicitly, confirm that TheTrueHOOHA is Snowden. However, you're a reasonable guy, so surely you can admit that this is pretty thin. Yes, there was "only" speculation about the link between the two prior to Ars' article, but it's not like the article offered any conclusive proof. 99% of the article was just rehashing what everyone else had already said.
Could they have worded it better? Yes. Does the way they did word it somehow push the article from "in poor taste" to "a grievous betrayal of trust"? Not in my opinion, no.
That is why I think categorizing this as some kind of "outing" or betrayal of trust is a huge overreaction.